The three candidates chosen were the third sitting councillor Andrew Sherris along with Mark Chatburn, who works for the Insolvency Service and Ben Houchen, a solicitor.

Cllr Beaumont said: “I was disappointed initially at the decision but I sat back and realised it was perhaps time to move on and let more young people take over.

“The two new candidates are close friends of the MP (James Wharton) and that will enable them to form a good team.

“I will move on and do something else.

“There is no rift between me and the party or anyone in the party. Young people want to come in and get involved and that is a good thing.”

Councillor Ken Lupton, leader of the Conservative Group on Stockton Council, said: “Jennie has done an excellent job for the borough. She has represented the residents of Yarm exceedingly well.”

Cllr Lupton said Cllr Beaumont had a wealth of experience in planning and in her environment role her successes included the development of the Care for Your Area service.

Ian Gellatley, chairman of the North East Conservatives, said: “Everyone in the party is full of admiration for the dignified and optimistic way Jennie is looking forward to her retirement from local government.”

James Wharton, MP for Stockton South said: “Jennie has done a great job in representing residents in Ingleby Barwick, Yarm and Kirklevington. We will continue to have an excellent team in Yarm and I look forward to working closely with them.”

Cllr Beaumont was first elected to Stockton Council in 1979 and served as the borough’s mayor in 2004-05. She represented the Ingleby Barwick ward and saw it grow to become Europe’s largest private housing estate.

In the last council elections in 2007 Cllr Beaumont topped the poll in the Yarm Ward.

Cllr Beaumont described her 32 years as a local councillor as “one long, fascinating experience”.

“Working with the original plan was restrictive and put a lot of responsibility on councillors. The fight to get the first secondary school was a big event and the whole community got behind me,” she said.

“I will also miss my work on planning. It has changed tremendously over the years and it is always a challenge. Planning is not a perfect science and some decisions are not easy.”

She said her environment role presented a tremendous learning curve.

“I will miss it but I hope to keep an interest going in issues such as climate change and waste management. Over the years I have enjoyed working for people and with people and I remain upbeat,” she said.